- 1894: Daimler engines take 1st to 4th place in the world’s first car race
- Epoch-making Grand Prix victories in 1908 and 1914
- Supercharger era begins in 1922
The automobile with internal combustion engine was just eight years old when it proved successful in the first public race. The winners in this competition, held in France in 1894, were four vehicles with engines built using the Daimler system. This first officially organised trial of strength for cars was announced by the Parisian newspaper Le Petit Journal and went from Paris to Rouen.
The selection process was tough: 102 vehicles bid for a starting slot, 21 were deemed suitable by the judges to tackle the long distance and were allowed to participate. Only 15 cars reached the finish line. Of these, nine had a Daimler engine manufactured under licence. They included the first four finishers in the category internal combustion engine, featuring two-cylinder V-engines from Panhard-Levassor. The 3.5 hp engines (2.6 kW) permitted an average speed of 20.5 km/h over the 126 kilometre distance.
First place in 1894 was shared by a car of the Peugeot brothers and a Panhard-Levassor car. The V-engine of the Peugeot Vis-à-vis had two cylinders banked at a 17 degree angle. Vertically installed underneath the bench seat, the engine had a displacement of 974 cubic centimetres and developed 3.5 hp (2.6 kW) at 620 rpm.
Two more Peugeots took third and fourth place, and a Roger-Benz with 5 hp (3.7 kW) was fifth. In the years that followed, various cars driven by Daimler engines won a large number of victories and substantiated the fine reputation of state-of-the-art technology from Germany. Companies were quick to recognise the publicity value of such racing successes and began to turn them to good account to sell their vehicles.
Improvements to the competition cars entered directly into series production – if one can speak of that in view of the small unit numbers made mostly by hand. The first motor race in 1894 thus not only marked the beginning of motorsport in the modern sense, but also the start of dynamic technical developments in car manufacture, spurred on again and again by the spirit of competition. As a result, except for a few details the technical development of racing hardly can be distinguished from the development of production cars well into the first third of the 20th century.
At the same time, the first race for automobiles with internal combustion engines was a farewell event for the older steam technology: A De-Dion-Bouton steamer was the first car in the field to cross the finish line in 1894, but the exceedingly heavy vehicle did not comply with the competition rules because of its ponderousness, and therefore only was awarded second place as a token of honour.
In view of the rapidly improving performance of cars with petrol engines, races between steamers and cars with internal combustion engines became increasingly rare in the following years. Whereas steamers of various designs at least were admitted to this race, cars using other drive systems got no permission to start: electric cars, hydromobiles and cars driven by compressed air, gas, or electro-pneumatically were not allowed onto the 126 kilometre course.
Among the thousands of people who followed the race were Gottlieb Daimler and his son Paul, who later described his impressions of the day in these words: “On the early morning of the race day my father and I were not far from Porte Maillot near Paris. Huge crowds came to witness what was a unique spectacle in those days, the line-up of the cars for the start of the race.
The shape, size and design of all these racing cars were very different; heavy steamers with trailers, veritable powerhouses, competed against the lightest steam-powered three-wheelers, and these in turn with the petrol-powered cars; all had come for the same purpose: to be the first in Rouen and to arrive again in Paris at Porte Maillot.
We ourselves – Paul Daimler and Gottlieb Daimler – accompanied the field in a car. The different vehicle types made a curious impression; we watched the boilermen on the heavy steamers, dripping with perspiration and covered with soot, working hard to put on fuel; we could see how the drivers of the small steam-powered three-wheelers kept a watchful eye on the pressure and water level in the small, skilfully built tubular boilers and regulated the oil firing; and in contrast to that we saw the drivers of the petrol and paraffin-powered cars sitting calmly in the driver’s seat, operating a lever here and there, as if they were simply out for a pleasure trip.
It was a very strange picture, unforgettable for me….”
The following year it was a similar picture in the Paris – Bordeaux – Paris race over 1192 kilometres, regarded as the first genuine car race: among the first eight finishers were six cars equipped with Panhard-Levassor engines built under Daimler licence, and two Benz vehicles. In 1896 cars with Daimler engines then scored a triple victory on the Paris – Marseille – Paris run over 1728 kilometres at an average speed of 25.2 km/h. Again and again, Daimler engines had the upper hand in races in France, be it in the Paris – Dieppe race (triple victory) and Paris – Trouville race (victory) in 1897 or one year later in the Marseille – Nice (triple victory) and Paris – Bordeaux races (winner René de Knyff).
1898: Daimler cars win races on their own
However, Daimler-Motoren-Gesellschaft didn’t want to impress people merely as an engine designer, but win races with its own products. The Stuttgart people succeeded at this on 25 to 27 May 1898 in the Berlin – Leipzig – Berlin race, won by a Daimler car. Friedrich Greiner was seated at the wheel and completed the race with an average speed of 24.3 km/h. Shortly before this, also in May 1898, the first-ever German car race had been staged, from Berlin to Potsdam and back.
In his chronicle of the racing history of Mercedes-Benz, automotive historian Karl Eric Ludvigsen tells the story of this birth of motorsport on German soil in the style of a commentary: “A few inquisitive souls had turned up to see the departure of thirteen chugging, shaking horseless carriages with their own eyes. It was the start of the first automobilists’ competition in the German Empire. The cars roared off down the rutted main road in the direction of Potsdam.
The little city had been chosen as turning point from which the participants would set off on the return trip. Potsdam also was the residence of one of the first German promoters of motorisation – Kaiser Wilhelm II. The 54 kilometre drive was a historic event for another reason too, because for the first time cars of Daimler and Benz were at the start.”
There were various other events. The first Dolomites race in August 1898 around Bolzano was won by Wilhelm Bauer and Wilhelm Werner in their Daimler Viktoria car. The race, dominated by the 7.5 hp (5.5 kW) vehicle with a two-cylinder engine, is regarded as the first controlled long-distance run through the Alps in automobiles – and again it was Daimler that set the trend in the young history of motorsport.
A year later Wilhelm Bauer also won the Nice – Colomars – Tourettes – Magagnone – Nice tour for two-seaters. The race was an event of the ‘Nice Week’. Arthur de Rothschild finished second. Both drivers steered a Daimler Phoenix model with 12 hp (8.8 kW). Wilhelm Werner in a 12 hp Daimler Phoenix crowned the success of the German brand with a win in the four-seater car class.
Also in 1899, Daimler cars scored a double victory in their class in the first Semmering race. In motor racing circles, in future one would hear a lot about the driver of the winning vehicle, a 12 hp Daimler Phoenix: it was Emil Jellinek, businessman and insurance agent from Vienna. In 1897 he ordered his first Daimler car. In 1898 he bought the world’s first two road vehicles fitted with a four-cylinder engine (8 hp Daimler Phoenix models with front-mounted horizontal engine).
Jellinek not only drove Daimler cars himself, but sold DMG automobiles as well, delivering the vehicles from Stuttgart mainly to members of the upper crust – with rapidly rising success: in 1899 DMG delivered ten cars to Jellinek, in 1900 he already took 29. Meanwhile, the Austrian was calling for more and more powerful, faster cars which he also personally entered in racing events. His participation in the Nice Weeks, where he competed under the pseudonym ‘Monsieur Mercedes’, would become famous. Jellinek was inspired to use the name by his daughter Mércèdes, born in 1889.
In April 1900 ‘Mercedes’ became the product designation when Jellinek and DMG signed an agreement on the sale of cars and engines and Daimler promised the development of a new engine that was to be called ‘Daimler-Mercedes’. A short time later, within a few weeks Jellinek ordered a total of 72 cars of different outputs from DMG – in 1900 this was truly a major order. The first car equipped with the new engine, a 35 hp racing car, was delivered on 22 December 1900.
In this first Mercedes, designed like many vehicles before it by Wilhelm Maybach, the development of the modern car experienced a first climax. The dynamic evolution from carriage-like motor vehicle to automobile with a design idiom of its own had been under way for some time. But Maybach, chief design engineer of DMG, managed a seminal stroke of genius with this racing car. The automobile had a 5.9-litre front-mounted four-cylinder engine whose formidable 35 hp (26 kW) permitted a top speed of no less than 100 km/h. Other features included a low centre of gravity, a pressed steel frame, a lightweight engine design, and the revolutionary honeycomb radiator.
In addition, in a record-breaking attempt during the Nice Week Lorraine-Barrow attained an average speed of 79.7 km/h over the mile with standing start in a 35 hp Mercedes to set a new world record for the mile. The Daimler racing cars were practically unbeatable in all disciplines, which guaranteed extraordinary publicity to Jellinek and thus to DMG and found expression in corresponding demand.
The successes of the new car impressed experts and the general public. Paul Meyan, secretary general of the French automobile club, acknowledged the new supremacy of the German automobile brand Mercedes on the courses which long had been dominated by French makes: “Nous sommes entrés dans l’ère Mercédès” (We have entered the Mercedes area), he wrote after the Nice Week of 1901.
1903: Gordon Bennett Trophy race victory in Ireland
The 35 hp Mercedes racing and touring cars already were replaced by the 40 hp Mercedes Simplex in 1902. The car rightfully bore this name: Wilhelm Maybach thoroughly designed it for more power, simpler operation and greater reliability. In a 40 hp Simplex racing car Count William Eliot Zborowski took second place in the Paris – Vienna long-distance race in June 1902 (the third competition in the series of legendary Gordon Bennett Trophy races).
The Gordon Bennett Trophy was perhaps the most important competition series in international motor racing. The American publisher and editor of the New York Herald, James Gordon-Bennett, who lived in Paris, created this race at the end of 1899. It was held once each year as a competition of nations.
The cars had to weigh at least 400 kilograms, but no more than 1000, and had to be manufactured down to the very last screw in the country for which they competed. The nation that fielded the winner was allowed to organise and hold the race the next year.
The Gordon Bennett races of the early 20th century originated the tradition of national colours for racing cars. DMG started for Germany in cars with a white paint finish. Other colours which became established during these years were dark green for England, red for Italy, blue for France, black and yellow for Austria-Hungary, red and yellow for Switzerland, and red and white for the United States of America.
As the British driver S. F. Edge in a Napier had won the 1902 race, the 1903 race was to take place in England. But road races were prohibited there, so the competition was moved to Ireland. DMG intended to start there with the new generation of Mercedes Simplex racing cars, using the more powerful variant with 90 hp engine (66 kW) specifically built for competition. However, the 90 hp car fell victim to the major fire that gutted the Cannstatt factory on 10 June 1903. So on 2 July three 60 hp Mercedes Simplex took the start in Ireland. DMG had bought them back or loaned them from private customers who had sporting ambitions.
The Daimlers drove to Ireland under their own power at the end of June – and went on to victory. The Belgian Camille Jenatzy crossed the finished line first in the car of the American enthusiast Clarence G. Dinsmore. At an average speed of 79.24 km/h, Jenatzy scored the first significant international victory for DMG.
As a consequence of the Daimler triumph, the next Gordon Bennett Trophy race, in 1904, was held in Germany. On a circuit near Homburg in the Taunus region, French driver Leon Théry came out on top. This time Camille Jenatzy in his Mercedes 90 hp racing car only came in second, followed by Baron de Caters in a second Mercedes. Three more cars of this type started for the Austrian Daimler works in Wiener Neustadt, two of them finishing fifth and eleventh.
1906: The Grand Prix era begins
The 90 hp Mercedes of 1904 was almost identical with the previous year’s model, several specimens of which were destroyed in the big fire in the DMG Cannstatt factory in June 1903. One major change was however the reduction of the bore from 170 to 165 millimetres. The disadvantage of a smaller displacement was offset by raising engine speed from 950 to 1150 rpm. While Camille Jenatzy was unable to repeat his prior-year performance in the Gordon Bennett Trophy race, Hermann Braun won the sixth Semmering race in 1904 in a new record time at an average speed of 73.2 km/h.
The racing cars for the 1905 season also built upon the Maybach designs of 1903 and 1904. Apart from a few minor changes to the chassis, mainly the engine was modified: The total displacement of the four-cylinder was now gigantic 14.1 litres, and the engine output increased to 120 hp (88 kW) at 1200 rpm.
However, DMG was unable to score any major successes with the car, either in the final elimination round for the Gordon Bennett Trophy in France or in the Vanderbilt Cup on Long Island outside New York City. The causes were mainly valve damage and lost time due to frequent tyre changes.
For the 1906 racing season DMG developed a first racing car with six-cylinder engine. As early as in autumn 1905, Maybach had developed an extremely advanced unit with overhead camshaft, overhead valves and double high-voltage sparkplug ignition.
The engine had individual steel cylinders fitted to a light-alloy crankcase. Cooling jackets and cylinder head were designed as a common casting and welded to the steel cylinders. This fundamental design served Mercedes and Mercedes-Benz for several decades as a model for high-performance engines.
With cylinder dimensions of 140 x 120 millimetres and a total displacement of 11.1 litres the six-cylinder developed 106 hp (78 kW) at 1400 rpm, or 120 hp (88 kW) at 1500 rpm. Never before had such high engine speeds been realised in engine manufacture. Maybach made them possible by keeping all moved masses in the valve train to a minimum. However, he did not receive the necessary support for his forward-looking engine, which was up against a six-cylinder of conventional design constructed by Gottlieb Daimler’s son Paul.
Finally, DMG made a Solomonic decision: for the 1906 season three vehicles would be equipped with the Maybach engine and three with the Daimler engine. However, the internal dispute resulted in a delay in production so that the Stuttgart company had to compete in the French Grand Prix in June 1906 with three largely unchanged 120 hp four-cylinder cars. In this first modern Grand Prix in automotive history, Mercedes only finished tenth and eleventh. Hermann Braun gained victory in the Semmering race on 23 September 1906 also in a 100 hp Mercedes with four-cylinder engine. This success – Braun set a new record again with an average speed of 77 km/h – finally made Braun the winner of the first Semmering challenge cup.
After a disappointing season all in all, DMG wanted to be better prepared for the 2007 racing year. The new 120 hp Grand Prix car was based in many ways on the 1905 model that was then used in modified form also in 2006. The frame side member with offset over the front axle and the more flatly mounted front leaf springs came from Maybach’s six-cylinder racing car.
For the first time DMG also used friction dampers. But the engine again was designed as a four-cylinder with a total displacement of 14.4 litres comprised of two pairs of cylinders from Paul Daimler’s six-cylinder. In the French Grand Prix on 2 July 1907 the Mercedes of Victor Héméry was the only Mercedes to reach the finish, coming in no better than tenth.
Mercedes enjoyed more success with its participation in races at the new Brooklands circuit in England: In the inaugural race on 6 July 1907, J. E. Hutton in a 120 hp Mercedes won the Montague Cup and prize money of 1400 pounds, followed by Dario Resta in a car of the same model. Mercedes cars won many more races in the first Brooklands season. On 5 August J. E. Hutton won the Heath Stakes, while on the same day Dario Resta emerged as winner in the Prix de la France race held on the British circuit, with Hutton coming in second.
1908: Victory in the French Grand Prix
On its third try Daimler managed to win the French Grand Prix. On 7 July 1908 Christian Lautenschlager won victory in Dieppe in the new 140 hp Mercedes Grand Prix racing car, coming in ahead of two Benz cars. Forty-eight cars, nine from Germany, participated in the 769.88 kilometre race on public roads. Actually, France wanted to underscore its role as ‘Grande Nation’ of motorsport with this race before a spectacular backdrop created by some 300,000 spectators. But the triple victory of the German racing cars dashed this hope.
The course with its many potholes made the Grand Prix a torturous undertaking for men and machines. Some teams dropped out only because they had not stocked enough replacements for the many tyres that were destroyed by the poor roads.
The tyres of the Mercedes cars also were given a beating. Christian Lautenschlager alone (the subsequent winner) changed 22 tyres during the race. Despite the unfavourable conditions, Lautenschlager crossed the finish line in first place after six hours, 55 minutes and 43 seconds, barely nine minutes ahead of the runner-up. His average speed over the entire distance was impressive 111.1 km/h. Teammate Otto Salzer turned in the fastest lap in 36 minutes and 31 seconds, which equates to an average speed of 126.5 km/h.
In its issue No. 29, 1908, the Allgemeine Automobil-Zeitung summed up: “Lautenschlager was greeted by a band playing the German national anthem. The spectators in the stands applauded; the driver was not in the least fatigued. It was wonderful to see how the Mercedes ran around the course. Pöge drove a very bold race and overcame his weariness; Hémery and Hanriot likewise had good chances of winning. Erle was not very familiar with the course, but did an extraordinarily good job.”
The engine of the racing car had twin camshafts in the cylinder block, overhead intake valves, and side exhaust valves. The in-line four-cylinder thus accorded with the concept developed by Wilhelm Maybach for the designs of the racing four-cylinders of the years 1903 to 1906.
With a displacement of 12.8 litres the engine developed an output of 135 hp (99 kW) at 1400 rpm. The winning car of Dieppe also was the basis of the Semmering car, a 150 hp Mercedes in which Otto Salzer came out on top in the tenth Semmering race on 20 September 1908 on his first participation in the open racing car class. In doing so Salzer set a new record with an average speed of 81.2 km/h. One year later Salzer raised the benchmark once more with a speed of 84.3 km/h. In 1910 the engine received aluminium pistons and attained an output of 180 hp (132 kW). The vehicle fitted with this engine ended its career on a fantastic note on 16 July 1910 by reaching a top speed of 173.1 km/h over the flying kilometre during the Ostende Week (Belgium).
The first French Grand Prix marked the birth of modern formula racing. But it would take a while for a continuous series to develop out of this one-time event: Because of the high entry fees the leading car brands boycotted the Grand Prix planned for 1909 so that it had to be cancelled. A new French Grand Prix would not be staged until 1912. During this period, DMG did not allow any more factory teams to enter races, but continued to build top-flight racing cars for private buyers.
The 37/90 hp Mercedes introduced in 1911 was a high-performance car aimed precisely at this group. Its 9.5 litre four-cylinder engine had a combined battery and magneto ignition with two sparkplugs per cylinder. An interesting design detail is the three-valve technology realised for the first time at Mercedes: two exhaust valves and one intake valve per cylinder, conventionally controlled with pushrods and rocker arms by a camshaft in the cylinder block.
In several racing cars an uprated version of this production engine saw use. From 1911 to 1913, two of these cars, with Spencer Wishart and Ralph de Palma at the wheel, scored numerous racing successes in the USA. Both specimens had wooden spoke wheels and were fitted with a V-shaped radiator cowling. In another car that took the start with wire spoke wheels and a normal radiator without fairings in the French Sarthe Grand Prix on 4/5 August 1913, the Belgian Léon Elskamp finished seventh.
In 1913 DM planned to return to Grand Prix racing and built an entirely new 100 hp Grand Prix Mercedes fitted with two units which originally were design as aeroengines. The two engines took second and fourth place in the Emperor’s Prize competition for the best German aeroengine in January 1913. Featuring an overhead camshaft and overhead valves they had many points in common with Maybach’s trailblazing six-cylinder racing engine of 1906.
The 7.2 litre DF 80 six-cylinder that came in second in the Emperor’s Prize had individual turned steel cylinders, fitted in pairs with welded-on sheet steel cooling jackets. It had an output of 90 hp (88 kW) at 1400 rpm. The large-displacement four-cylinder G 4F, awarded fourth place in the Emperor’s Prize competition, even mobilised 100 hp (74 kW) at 1350 rpm from its 9.2 litres cubic capacity. However, the cars were unable to start in the 1913 French Grand Prix on the circuit in the Picardie: as they were not entered by the factory itself, but by the Belgian agent Theodor Pilette, the Automobile-Club de France rejected the entry.
But at least three of the new cars would see action three weeks later in the Grand Prix de la Sarthe: Pilette in his 100 hp (74 kW) four-cylinder car was in second place for much of the distance and finished third after suffering a tyre defect – a reasonably successful performance if anything. His teammates Otto Salzer and Christian Lautenschlager came in fourth and sixth in their 90 hp six-cylinder cars (66 kW). With frame side members slightly tapering to a V at the front and pointed radiators, all three cars were alike as peas in a pod.
However, on its left side the four-cylinder car had four exhaust pipes running into the manifold, whereas the six-cylinder cars had three exposed exhaust pipes. In the same race Léon Elskamp, driving an older 37/90 hp Mercedes based on the 1908 Grand Prix car, took seventh place. Elskamp won the 1913 Grand Prix of the Belgian Automobile Club in Spa in a Mercedes-Knight 16/45 hp with an average speed of 99.7 km/h.
Mercedes finally surpassed its success in the 1908 French Grand Prix by scoring a triple win in 1914 with Christian Lautenschlager, Louis Wagner and Otto Salzer at the wheel of 115 hp Mercedes Grand Prix racing cars. This vehicle had a four-cylinder engine of all new design with overhead camshaft plus two exhaust valves and two intake valves per cylinder – realising four-valve technology in a Mercedes engine for the first time.
The engineers designed the racing engine for a continuous-duty engine speed of 3500 rpm, a truly sensational figure for those days. A new feature compared with the previous Grand Prix cars was the change from chain drive to propeller shaft drive.
On 4 July 1914 the Mercedes team took the start in the French Grand Prix in Lyon with five of these cars against supposedly overpowering competition. Theodor Pilette and Max Sailer had to give up because of technical problems, but in the remaining cars Christian Lautenschlager, Louis Wagner and Otto Salzer gained a triumphal triple victory that underscored, and clearly exceeded, the Mercedes success of 1908.
The engine with the internal designation M 93654 is regarded as a landmark design. And it even served as model for Rolls-Royce aeroengines in the First World War: After the victory in Lyon, a vehicle was sent to England for demonstration purposes. The beginning of the war caught it by surprise, and it remained in England. Engineer Walter Owen Bentley knew what the car was worth and had it dismantled and analysed at Rolls-Royce. Bentley adopted the design of the valve train for his own engines.
While the war put an end to further racing activities in Europe, at least one of the 1914 Grand Prix cars continued to compete in the USA: Ralph de Palma bought one of the winning cars and scored a great many victories with it in the USA from 1914 to 1917.
His most spectacular performances included the winning of the Indianapolis 500 on 31 May 1915. After the war’s end the 4.5 litre car again saw action in Europe in several races. A particularly successful driver was Count Giulio Masetti, who won a number of races in Italy in 1921 and 1922, including the Targa Florio in April 1922. At this event the DMG factory also was represented by two Grand Prix cars, but got nowhere against Masetti.
1921: A new beginning after the First World War
When the war came to an end in 1918, any smooth continuation of the racing activities of Mercedes was out of the question. The restrictions placed on German and Austrian drivers in important competitions like the French Grand Prix by themselves were enough to cause a break. And so the first post-war racing sports car presented by Daimler-Motoren-Gesellschaft was not an entirely new development, but based on the 28/95 hp Mercedes racing tourer of 1914. This racing sports car, fitted with a new engine featuring among other things cylinders cast in pairs, started to bring success for Mercedes drivers in 1921.
In the Königsaal-Jilowischt mountain race on 25 May 1921, in a two-seater sports car with shortened wheelbase Otto Salzer posted the best time for all classes and a new course record to boot. Suitability for long distances was demonstrated at the Targa Florio in Sicily, where on 29 May factory driver Max Sailer came in second in the overall ranking and won the Coppa Florio, the prize for the fastest production car. Sailer converted his racing car himself and drove it to Sicily under its own power.
A year later Sailer was back in Sicily with the 28/95 hp Mercedes. The engine meanwhile had a supercharger which enabled raising its output to 140 hp (103 kW). Sailer was the winner in the over 4.5 litre production car category and finished sixth overall.
1922: Dawn of the supercharger era
Two completely newly developed 1.5 litre racing cars of type 6/40/65 hp featuring supercharged engines also took the start for Mercedes in the 1922 Targa Florio. The Sicilian race thus was the first where Stuttgart’s supercharged cars saw action. However, the overall winner of the 1922 Targa Florio was not a mechanically charged vehicle, but the 1914 Grand Prix racing car driven by Count Giulio Masetti. In the vehicle that Ralph de Palma took to the United States in 1914, Masetti also won the Italian Grand Prix in Brescia in September 1921 and the Pontassieve – Consuma race in June 1922, as well as lesser races.
DMG no longer was allowed to build aeroengines after the war. But the experience with the mechanical charging of aircraft powerplants now benefited the vehicle engines from Stuttgart.
At the end of 1921 DMG saw a good opportunity to participate in the voiturette class of racing cars. Their displacement was limited to 1500 cubic centimetres. This was an interesting class of cars because it was widely accepted in England and Italy, which were regarded as potential markets and worldwide disseminators. The M 68084 engine of the 6/25 hp supercharged car that had just been introduced in Berlin provided a practicable starting point, even though its displacement of 1.6 litres exceeded the limit set by the racing regulations.
The design of this base engine was thoroughly revised for racing use so that it even became the standard for all Mercedes and Mercedes-Benz racing engines down to the 1950s. The bore-stroke ratio was changed to 65 x 113 millimetres to give a displacement of exactly 1499.87 cubic centimetres, utilising the 1.5-litre limit prescribed by the rules almost to the last hundredth. Untertürkheim also pursued a different path in cylinder head design by constructing a purebred racing engine with two overhead camshafts and four acutely angled overhead valves.
The sparkplug was optimally located in the centre of the combustion chamber between the two pairs of valves. As in the base engine the camshafts were driven by a vertical shaft, which in this case, however, took the form of a transverse shaft for both camshafts.
The high-tension magneto and the water pump were driven by transverse shafts farther down in the engine. While the vertical shaft was placed at the end of the crankshaft, the vertically positioned Roots blower was driven with a ratio of 1:1.9. Compared with the 1.6 litre engine the supercharger was appreciably enlarged and could be engaged and disengaged by a cone clutch which was actuated by flooring the accelerator, similar to the kickdown effect of future automatic transmissions.
The output of the racing engine was stated as 40 hp (29 kW), with supercharger 65 hp (48 kW). However, measurements made in 1948 showed an output of almost 80 hp (59 kW) with supercharger. In the naturally aspirated mode the engine was about on a level with competitors such as the Fiat 403, which on the other hand responded far more sensitively to accelerator positions than the supercharger with its sudden bursts of power – much like the early specimens of the turbocharged engines that emerged later.
24 units of the Mercedes-Benz high-performance engine were built at the time, three of them for use in powerboats and the other 21 in vehicles. The brakes were adapted to the high power (four-wheel brakes in the Targa Florio cars, for example).
The 1.5 litre racing car saw its first racing use in April 1922, with two of them entered in the Targa Florio in Sicily alongside two 1914 Mercedes Grand Prix racing cars and two 28/95 hp racing tourers, one of which also was fitted with a supercharger.
Paul Scheef merely managed an overall 20th place finish with one of the two 1.5 litre supercharged cars; Italian driver Fernando Minoia in the second supercharged car even had to retire from the race. Despite this somewhat unlucky start, the 6/40/65 hp established a whole ancestral line of supercharged racing cars which, beginning in 1924, achieved remarkable successes for the Mercedes und Mercedes-Benz brands and gained world fame.
The near-series 6/25/40 hp sports tourer was used in numerous events with great success starting in 1923. It was in one such vehicle that Rudolf Caracciola enjoyed his first successes for Mercedes. For example, in a Mercedes 6/25/40 hp he won the ADAC Reich Rally from 19 to 21 July 1923 in the class of touring cars up to 6 tax hp.
The Mercedes two-litre Indianapolis racing car, also developed in 1923 on the basis of the 10/40/65 racing sports car, was the last car designed for DMG by Paul Daimler. The vehicle, which with supercharger developed 150 hp (110 kW) at 4800 rpm, featured a roller-bearing-mounted crankshaft and an oil cooler for the first time. In the 500 mile race in Indianapolis, USA, Sailer and Werner came in eighth and eleventh in the car.
Ferdinand Porsche as new chief design engineer at DMG developed the 1924 Targa Florio racing car on the basis of the Indy car. Numerous detailed improvements made the racer a very promising contender for victory.
But in this race the preparatory work done by DMG in advance of its participation in April 1924 was on an extremely high level: Already in January, Stuttgart sent two test cars to Sicily, painting the cars red instead of the usual white for a very special reason. This was not a friendly gesture to the host country, but shrewd tactics: as spectators could recognise the racing cars of other nations by their colour from a large distance, many of them hurled rocks at unpopular rivals from outside Italy.
Camouflaged in red, the racing cars from Stuttgart were spared this fate. Christian Werner won the 540 kilometre race. Lautenschlager finished in tenth place, and a new driver on the DMG team finished 15th: young Alfred Neubauer would write racing history for Mercedes-Benz in future – not as a driver but in the role of racing manager.
After the Targa Florio the car was used in other races. For the 1924 Semmering run, Otto Salzer even had the 4.5 litre engine of the 1914 Grand Prix installed in the chassis, additionally fitting it with a supercharger. With ‘grandmother’, as Salzer dubbed the monster, he scored victories in sprint and mountain races including Semmering in September 1924. Later, Rudolf Caracciola, Alfred Rosenberger and others competed in this vehicle.
Less successful than the Targa Florio car was the Porsche-designed eight-cylinder ‘Monza’ racing car that also was introduced in 1924. This first DMG car with eight-cylinder engine was the first independent design created by Ferdinand Porsche in his new function as chief design engineer of Daimler-Motoren-Gesellschaft.
In the Italian Grand Prix in Monza in October 1924 the white, two-litre Grand Prix cars appeared with fierce-looking radiators and bonnets. But the 170 hp (125 kW) car with the newly designed supercharged eight-cylinder powerplant proved to be very hard to control and very problematic. Count Zborowski, one of the drivers along with Masetti, Neubauer and Sailer, lost his life in an accident in this race. The biggest victory of the Monza car would be achieved in the 1926 German Grand Prix with Caracciola at the wheel.
Another highly spectacular automotive creation, dating from 1924, was based on an idea of Christian Werner and Alfred Neubauer: the racing car transporter based on a Mercedes 24/100/140 hp looked rather rustic, but it provided for the speedy, safe transport of the competition cars. Before that they had to travel to the scene of races under their own power, if necessary. In 1955 Mercedes-Benz was to take up this idea of a fast transport vehicle again and complete it by creating the elegant Silver Arrow transporter.
The last great racing car presented by DMG before the merger with Benz & Cie. was the model K of 1925. The Mercedes 24/100/140 hp Model K Racing Tourer, as the vehicle was called with its full name, was planned as a heavy, sporty touring car with an in-line six-cylinder engine. “But it was a racing car that designer Porsche served up,” writes Karl Eric Ludvigsen about the ‘K’. This powerful and fast supercharged Mercedes with up to 160 hp (118 kW) and a top speed of up to 124 km/h founded the legendary family of heavy supercharged cars from Mercedes-Benz: models S, SS, SSK and SSKL dominated the racing scene for many years beginning in 1926.